diff options
| author | Michael Hennerich <michael.hennerich@analog.com> | 2009-02-04 16:49:45 +0800 |
|---|---|---|
| committer | Bryan Wu <cooloney@kernel.org> | 2009-02-04 16:49:45 +0800 |
| commit | a2be3931144b8fab73c3d876c148ada7a3c09066 (patch) | |
| tree | 9a69e48cfa69c2b1191299e3493a3b2416753ed3 /arch | |
| parent | 5e7bb132bbed2088b8b103e410d143b341dcb837 (diff) | |
Blackfin arch: reset POLAR setting when acquiring a gpio for the first time
when requesting a GPIO for the first time, the POLAR setting is not
set to a sane state. this can lead to indeterminate behavior that
cannot be resolved without an explicit write to the Blackfin port POLAR
register.
when requesting a GPIO for the first time via gpio_request(), the POLAR
setting for the GPIO in question should be set to sane state. this
should occur if the GPIO has not been allocated in any other way.
some examples:
- when doing something like "request_irq(); gpio_request();" on the
same GPIO, the POLAR setting should not be reset.
- when doing "gpio_request(); gpio_request();" on the same GPIO, the
POLAR setting should be reset only the first time and not the second.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/blackfin/kernel/bfin_gpio.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/arch/blackfin/kernel/bfin_gpio.c b/arch/blackfin/kernel/bfin_gpio.c index ea67ae5b033..0c4fc31029c 100644 --- a/arch/blackfin/kernel/bfin_gpio.c +++ b/arch/blackfin/kernel/bfin_gpio.c @@ -1053,9 +1053,15 @@ int bfin_gpio_request(unsigned gpio, const char *label) local_irq_restore_hw(flags); return -EBUSY; } - if (unlikely(reserved_gpio_irq_map[gpio_bank(gpio)] & gpio_bit(gpio))) + if (unlikely(reserved_gpio_irq_map[gpio_bank(gpio)] & gpio_bit(gpio))) { printk(KERN_NOTICE "bfin-gpio: GPIO %d is already reserved as gpio-irq!" " (Documentation/blackfin/bfin-gpio-notes.txt)\n", gpio); + } +#ifndef BF548_FAMILY + else { /* Reset POLAR setting when acquiring a gpio for the first time */ + set_gpio_polar(gpio, 0); + } +#endif reserved_gpio_map[gpio_bank(gpio)] |= gpio_bit(gpio); set_label(gpio, label); |